A dominant leader is the face of and sets the culture for their party. With such leaders, strong supporters can feel a rapport and instinctive trust grounded in common values. More sceptical voters can still have confidence in a basic approach and competence. Opponents have to grudgingly admit how tough their task is. Communication - cutting through to everyone - is key.
Like character actors next to a leading light, other politicians may have noticeable ability, appeal and worth, and yet still fall short. They might have a connection with a section of the electorate but chemistry with the broader public isn't there.
The definition of hell for a political party is probably the period after it has lost its own dominant leader - if it then also has to oppose the new reign of rival one.
Labour went through this after Clark and while Key was in power. The end result: four opposition leaders in about eight years with another - Ardern - after Bill English took over as prime minister.
Judith Collins is National's fourth opposition leader since 2017. A succession of poor polling results has spawned media speculation that the party could be about to get its fifth. It could mean a comeback of Quade Cooper proportions for former leader Simon Bridges.
Collins has Thatcher-like leadership attributes such as a distinctive personality, toughness, and an air of authority. There's also some relatability and humour. Her abrasive scrappiness, which appeals to some but puts off many, has been an uneasy fit during a serious crisis when people sought unity, safety and competence. A different time could have aided her cause.
A positive way of navigating this pandemic-shaped period has been shown by Chris Bishop's approach to his coronavirus brief: stay in tune with the public's desire for the response to go well, while pointing out where things could be improved, and highlighting other options.
The Government faces a challenging period of planning for reopening with many practical issues to deal with, alongside difficult non-pandemic problems such as climate, and housing. This is occurring amid widespread Covid fatigue.
The Delta outbreak has spurred a stepped-up Covid response with a clear attempt to get ahead of the curve on vaccinations after regular complaints this year of the Government being too reactive.
Ardern's Government holds the advantage if it handles the next few months well. But this should also be fertile ground for an opposition charged with holding the Government to account. Some of the more casually attached voters who supported Labour at the last election could be wooed away.
National is in effect still searching for its new Key. At this stage a new English might be a more realistic bet if the party takes the gamble. Someone, if there is one, whom people can feel comfortable with, who can credibly debate issues with a depth of knowledge, and present alternatives.